Light-flashing relay



March 31. 1925.

A. H. DAVIS LIGHT FLASHING RELAY Filed July 6, 1923 Fig}. I

Ihvento'r- I Archibald H. Davis,

His Attorney.

Patented Mar. 31, 1925.

- UNITED" STATES ARCHIBALD H. DAVIS, OF BUFFALO, NEW YORK, ASSIGNOR TO GENERAL ELECTRIC.

4 1,532,045 PATENT OFFICE;

OOMPAN'Y, A CORPORATION OF NEW YORK.

LIGHT-FLASHING RELAY.

Application filed July 6, 1923. Serial No. 649,798.

To, all whom it may concern:

Be it known that I, ARCHIBALD H. DAVIS, a citizen of the-United States, residing at Buffalo, county of Erie, State of New York, have invented certain new and useful Improvements in Light-Flashing Relays, of which the following is a specification.

My invention relates to relays and particularly to that class of relays which are especially adapted for use in controlling the light 'flashes of electric. flash-light buoys where an uninterrupted automatic operation is required over extended periods'of time.

.An object of my invention is to provide an automatically operating relay which shall have a comparatively long period or cycle of operation. Another object is to provide a relay whose operation will not be material 1y aflected by variations in position or by wave motions to which the buoylmay be normally subjected. A further object is to provide an armature mounting for such a relay in which wear on the bearings will not appreciably aifect the alinement of parts or the proper functioning of the relay.

My invention will be better understood by reference to the accompanying specification and drawing and its scope will :be pointed out in the appended claims.

Fig. 1 is a planpartly in section of a device lnvolving my invention;

Fig. 2 is a vertical section of the same taken on the line 22 of Fig. 1;

Fig. 3 is a perspective view of the armature supporting lever, and

Fig. 4 is a circuit diagram.

Referring now to the drawing, a base plate 1, which may be of slate, has secured to it an angle bracket 2 carrying an electromagnet. -This magnet comprises a U-shaped core structure 3 formed of two parallel cores 4 joined together by a yoke 5. Each of the two cores shown is immediately surrounded by a comparatively thick sleeve 6 of good electrical conducting material, preferably copper, although several turns of heavy wire may be used if desired. Outside of these sleeves are the windings 7 and 8 which are suitably insulated both from the sleeves 6 and from the end plates 9 and 10 and which,

if desired, may be subdivided in two parts as shown. Two screws 11 serve to bind the sleeves 6 to the yoke 5 and to' angle brack- I an angle bracket 13 of non-magnetic material by which the armature is supported fits over the end of one. core 4 and is secured by means of. a bolt 14 to the base plate and by another screw (not shown) to the adjacent sleeve 6. The bracket 13 has two similar depending ears 15, one bein hidden.

by the other in Fig. 1, havin pivots 16 which support the lever 17 a so of nonmagnetic material. This lever, shown by itself in Fig. 3, has .at its right hand end two lugs or ears 18 through which extend the pivot pins 19 for the armature 20. The latter is a straight bar of soft iron and the pivot holes therein are located midway between the two ends and midway between the end of this spring is secured to the lever 17 and for convenience in making an electrical connection thereto may be provided with a pig tail 28 andterminal 29. A small screw 30 carried by the lever 17 passes through and limits relative movement of the spring 27 in one direction. The left hand end of the lever 17 is' greatly enlarged for the pur ose of forming a counter weight 31 which s iall balance the right hand end and the parts carried thereby about the axis of pivots 16 for all positions which the buoy may take. For adjusting the efiective weight of this counterweight a screw 32 ,is threaded into the end thereof. The entire moving system being thus balanced about the axis of pivots 15, the position of the buoy in which the apparatus is installed or the complex movements thereof due to wave action has little or no effect on the functioning of the apparatus.

In order to efi'ec't a greater delay in the movement of the armature 20 after the circuit of the electromagnet has been closed, I provide a special pole piece for the right hand pole of the magnet, This pole piece 35 has a U-shaped form, its yoke portion being secured to the base by a screw and nut 36 and its two leg portions extending on opposite sides of the armature 20. The upper leg fits over and firmly engages the adjaccnt ,core 4. of the electromagnet while the lower leg is free and lies beneath the armature. The free end of each core 11 is covered by a thin layer 37 of non-magnetic material to prevent the armature from sticking thereto. A pin 38 proiects from the lever 17 a sufiicient distance to engage the armature should it, upon deenergization of the magnet, tend to stick against the right hand pole of the magnet.

By reference to. Fig. 4 it will be seen that when the contacts controlled by the lever 17 are closed the battery 39 may supply current through one circuit 40 to illuminate the lamp 42, which is suitably mounted in the top of the buoy, not shown, and through another circuit 41 in shunt with the lamp circuit to energize the windings 7 and 8. As soon as these two circuits are closed the lamp is illuminated and the magnetic flux of the magnet begins building up. The sleeves 6 exert a strong retardin effect, both to the building up of the flux o the magnet when the circuit is closed and to the deca of the flux afterthe circuit is opened. further delay in the operation of the armature in response tothe closing ot the circuit results from'the efiect of dividing the flux path at the right hand end of the armature 20 by means of the special pole piece 35.'

As the adjusting screw '25 is backed ofi, the open circuit position of the right hand end of the armature 20 approaches the middle of the space between the two legs of the pole piece 35 and obviously as this position is approached the flux more equally divides in the two paths forward and backward from the armature 20. The position of the armature may be so adjusted that the resultant pull on the right hand end thereof may not become sufficient to draw the armature toward the right hand pole-face spacer 37 until the flux of the magnet has reached its full and final value.

The armature having been pulled toward the magnetic cores 4 by the magnet will al- 7 ways come to rest against both spacers 37,

which action will occur by reason of the pivotal connection between the armature and the lever 17 even though the pivots 16 become considerably worn. Upon separation of the contacts both the lamp circuit and the magnet circuit are broken; the lam becomes extinguished and the windings eenergized. The flux of the magnet thereupon begins to decay at a rate governed by the cross sectional area and the conductivity of the sleeves 6. The time required for the flux to change from a maximum to a minimum is also a functionof the difl'erence between these values, and'in order to take advantage of this fact the reluctance of the magnetic circuit is made as low as practicable. At length the armature drops back under the influence of the spring 22 to the position illustrated by Fig. 1 when the lam and magnet circuits are again closed an the cycle of operationis repeated. By suitably varying the several adjustments provided, the periods during which the lam is illuminated and during which it is ark may be varied within comparatively wide limits. An example of what has been found to be a satisfactory cycle of operation for certain uses'of this device is: duration of flash 0.25 to 0.6 of a second; duration of dark interval 1.5 to 3 seconds.

While I have described only one embodiment of my invention, I do not wish to be limited to the particular form shown and described as it will be apparent that many modifications therein may be made without departing from the seo e of my invention as set forth in the appen edclaims.

What I claim as new and desire to secure by Letters Patent of the United States, is:

1. A relay of the class described comprisin an electro-magnet, an armature ada ted to e attracted thereby, and means for de aying the attractive movement of said armature comprising a pole piece for said magnet havin portions extending on opposite sides of said armature.

2. A relay of the class described comprising an electro-magnet, an armature movably mounted opposite the poles thereof, and means for e aying the attractive movement of said armature after the magnet is energized comprising a pole piece for the magnet having portions arranged to convey the flux to opposite sides of the armature.

3. A relay of the class described comprising a U-shaped electro-magnet, an armature therefor pivotally mounted opposite the poles thereof, means for resiliently holding said armature away from said magnet, and means for delaying the movement of said armature toward said electro-magnet after the circuit of the same has been closed comprising a U-shaped pole piece for one of the poles of said magnet having its legs extending on opposite sides of the corresponding end of the armature.

4. A relay comprising an electro-magnet, an armature therefor, a pivotally mounted member having a portion for supporting said armature and a counterweight portion, and means for pivoting said armature at substantially its center of gravity to said member, said counterweight being arranged to balance said armature, said pivoting means and said supporting portion irrespective of the position of said relay.

5. A relay comprising an electro-magnet, an armature therefor, a support, a lever pivoted thereto at a point intermediate its ends, and a pivotal connection between one arm of said lever and said armature at substantially its center of gravity, the opposite arm of said lever forming a counterweight for the armature, the pivotal connection and the first mentioned arm.

6. A relay comprising an electro-magnet, an armature therefor, a support for said armature, a lever pivoted at a point intermediate i'ts ends to said support, apair of pivot points carried by one arm of said lever and engaging said armature on substantially its transverse gravity axis, a stationary contact, a cooperating spring contact secured to 52nd lever, a return spring connected to said arm of said lever, the opposite arm of said 15 lever being enlarged to form a counterweight.

In witness whereof I have hereunto set my hand this third day of July, 1923.

ARGHIBALD H. DAVIS. 

